Genetics and probability Science of Heredity

Heredity Chemical instructions passed from parent to offspring at fertilization (one time only)  Chemical instructions are chromosomes, genes, and DNA

Genotype Phenotype Observable traits Variation (differences) among species members Sexual reproduction, Gene Recombination, Crossing over, etc.

Genotypes A gene picture for a trait  Alphabet used to symbolize gene picture Examples  Dominant gene is symbolized in upper case most abundant variation in a population RR – dominant trait shown  Recessive gene is symbolized in lower case Can be hidden if with a dominant gene rr – recessive trait shown

Phenotypes The physical appearance for a trait  What is visible Examples - Mendel’s Peas  Dominant gene is a smooth pea most abundant variation in a population  Recessive gene is a wrinkled pea Can be hidden if with a dominant gene

Probability: The science of chance Not an exact science, but will predict the chances that an event may or should occur  Expressed as a fraction: ½, ¾, etc.  Read as 1 chance out of 2 chances

Probability Laws Probability Law #1  The more data that is observed means that the percent deviation will get smaller and the validity or reliability of the data will get better Probablity Law #2  The results of one trial of a chance event does not affect the results of later trials of the same event Probablity Law #3  The chance that two independent events will occur together is the multiplication product of their chances of occurring separately